Well you are right , self-control play a vital role in gambling, which may help to minimize losses when gambling. Because we all are aware that losses cannot be avoided or neglected, but one can manage his losses by having a good self-control. This the thing most gamblers lacks in this space that's why there are alot of sad stories how one lose a certain huge amount amount of money, for instance one would have lose only just small amount of money but due to not knowing when to stop .
I think Practicing self control is easier said than done, I say this because a lot of gamblers knows too well that gambling without self control can ultimately have disastrous outcome. And every single time they plan to gamble, some would always try as much as they can to prioritize self control over gambling with emotions, and every single time they find themselves losing control. So it's not just a matter of knowing the importance of self control because many gamblers have already experienced the effects of lack of self control and yet they still apply emotions whenever they gambler and end up regretting at las. Would you still say this is caused due to their ignorance of the importance of self control?
Gambling itself has a lot to do with emotions hence the earlier a gambler understand that very fact the better in order to be able to manage his emotions towards gambling. However, one of the major problem is the exit point that are at some point not always easy to determine, some times when a gambler is on the winning line he gamble more and when he is also losing he also tend to gamble more so he could stand chances of winning and may end up chasing losses hence, understanding the exit point is very point irrespective of whether we are winning or Lossing as not to be trapped or carried away by emotions and becomes devasted if things didn't go as expected.